Plasma arc torches are widely used in the cutting, welding, and heat treating of metallic materials. A plasma arc torch generally includes a cathode block with an electrode mounted therein, a nozzle with a central exit orifice mounted within a torch body, electrical connections, passages for cooling and arc control fluids, a swirl ring to control fluid flow patterns in the plasma chamber formed between the electrode and nozzle, and a power supply. Sustaining a plasma arc causes the electrode, nozzle, swirl ring, and shield to wear requiring routine replacement; as such, the component parts are known as “consumables”.
Gas cooled plasma cutting torches exist which allow the consumable component parts to be changed without requiring tools. However, these gas cooled torches commonly use the same fluid (e.g. air) to support the cutting process and to cool the torch. Because only a single gas is used in such torches, there is less of a need to segregate the different gases between the various torch components (through the use of seals, o-rings, and the like). As a result of generally looser alignment of the components, gas cooled torches tend to be generally easy to disassemble.
Liquid cooled torches, by comparison, require tight seals for segregating the different fluids/gases between the torch components. While these seals effectively control the fluid/gas flow between the different torch components, they also tend to hold the torch components tightly together. As a result, liquid cooled plasma cutting torches commonly require a specially designed tool to install and remove each consumable component part. For example, a specially designed tool is needed to install and remove the electrode, while another specially designed tool is needed to install and remove the nozzle, etc.